A computer/processor unit that uses direct memory access (DMA) to a double data rate (DDR) interface may follow industry standard. DDR protocol and operate using deterministic clock-crossing designs along a propagation path from the unit under test to the DDR controller to the data storage and back. A tester (e.g., automatic test equipment ATE) testing the unit under test may adhere to the deterministic rules to communicate with devices along the propagation path to provide functional DDR read data pattern vectors in a deterministic manner across volume units, and covering all corners of process, variation, temperature (PVT). As functional operating clocks for the computer/processor units and the DDR continue to operate faster with each generation, complexity in guaranteeing deterministic timing relationships across PVT may become very complex and expensive.